Old vs new design fuel pump? Merc 120 supplier that wont break the bank?

[fishrdan]

X2 (3-4 whatever) on NOT using an automotive fuel pump. I made that mistake before I knew any better, and quickly replaced the automotive pump with a marine pump when I found out what could happen - BOOM! There have been many cases of boats exploding in my area, due to fuel vapors in the bilge, and I dodged a bullet...

I have a 73 Mercruiser with a top filter fuel pump, and had access to a new style bottom filter pump, used one. The new pump wouldn't work properly on the older engine, mounting holes are slightly off, and the new style pump on the old engine wouldn't pump fuel properly, fuel starvation. The new style pump would bolt on, and run the engine, but it wouldn't run properly. I swapped it out with an old style top filter pump, which works perfectly.

It's a Carter fuel pump, and Airtex makes replacements for it. The old pumps are spendy, but I was able to get a new one for under $100 with some searching. I was never able to find a rebuild kit for the old style fuel pumps, probably due to liability.

Also, you should have a water separating fuel filter installed the pump (ethanol). With that, you can remove the fuel filter inside the pump, and not have to worry about servicing the up-side-down fuel filter.

 

[ianbword]

Took me a little digging but I found the same pump I needed for around $100 from Summit. I wasnt gonna mess around with a automotive pump. If anyone ever need the part number it can be found here.

https://www.summitracing.com/parts/CRT-M60032

I cant confirm how well it works yet because im waiting on the carb to be rebuilt, but the arm setup was the same. The fittings it came with were a little bit different but I cleaned and reused my stock ones so no big deal.


You guys mentioned the hose going back to the carb...what material is it made of? Mine is hard and shot.

Would it be wise to run a inline filter and if so should it be before the pump or after??

Thanks everyone

 

[thumpar]

It is tygon (sp?) I believe. It gets hard but doesn't hurt it so unless it is cracked I would use the one you have.

 

[hoowahfun]

You're fuel pump already has a filter in it, but you can also add a fuel/water separator between the tank and pump. I don't have one on my boat, but it's a good idea if you have the money or want a little extra peace of mind.

 

[ianbword]

You're fuel pump already has a filter in it, but you can also add a fuel/water separator between the tank and pump. I don't have one on my boat, but it's a good idea if you have the money or want a little extra peace of mind.

Id like to add one at some point for peace of mind.

 

[Planodave]

So you can interchange between the two? You have any issues with the hard line or the arm being different?

Sorry to revisit this, however this is my dilemma. I have swapped out a broken Merc 140 with a used hopefully not broken 140 that came without a fuel pump. The old style fuel pump bolts on but it looks like the space for the gasket has room at the top. (probably did not explain that very well. It looks like the arm that rides on the engine cam is pointing in opposite directions down versus up between the old and new pump designs. I don't want to break something as soon as I turn the motor over....Any help is greatly appreciated!
Thanks
Dave